1. Field of the Invention
This invention relates generally to medical devices for use during surgery and, more particularly, to tissue picks for use in endoscopic, laparoscopic, or other minimally invasive surgeries.
2. Related Art
Tissue picks are commonly used by surgeons, for example, to lift tissue such as peritoneum, pleura, endocardium, organ capsules, skin, or any other tissue, hereafter referred to as target tissue, during invasive surgical procedures. Tissue picks are also commonly used when separating fine target tissue from an underlying area such as an artery which is not to be cut.
A conventional tissue pick is formed of a rigid material in the shape of a relatively short rod-like device having a handle end attached to a tissue grasping end. The tissue grasping end includes a double-pronged tip. To use a conventional tissue pick, during surgery, a surgeon orients and manipulates the tissue pick such that the double-pronged tip grasps the target tissue. The surgeon then moves the tissue pick, together with the target tissue, to a desired location. A second surgeon or other medical assistant then manually holds the tissue pick in the desired location while the surgical procedure is performed.
With the advent of less invasive surgeries, such as laparoscopic, thoracoscopic or endoscopic surgeries, the use of conventional tissue picks is limited primarily due to the relatively short length and rigidity of the instrument. However, the need to lift or move a target tissue during minimally invasive surgery remains. Generally, in such invasive surgeries, the body cavity area where the surgery is to occur is generally filled with a gas, typically carbon dioxide, to inflate the cavity to about six inches or so, thereby separating the outer tissue layers from the surgical field. A plurality of laparoscopic trocars are inserted through the outer tissue layers so as to extend into the inflated body cavity. One trocar may be used to receive a small fiber optic video camera or other video device. Other trocars may receive the surgical instruments required to perform the intended surgery.
Tedious surgical procedures have been developed to move the target tissue during minimally invasive laparoscopic surgery. Common to such procedures is the creation of a small incision at a location remote from the laparoscopic trocar. This small incision must extend through the many layers of outer tissue before reaching the inflated body cavity. A surgical needle and suture is then manipulated through the small incision into the body cavity. With a pair of graspers through the same or another incision, the needle is grasped and pushed through the target tissue. The needle is then released and subsequently grasped on the other side of the target tissue with the graspers and pulled back out through the incision. The suture is then anchored in some well-known manner, and the target tissue is retracted or moved into position. Alternatively, a separate trocar can be placed for a grasper or other instrument.
The inventors of the present invention have recognized certain disadvantages with the above approaches. For example, the area of the body where the relatively large incision is made for insertion of either the tissue pick or needle and suture is traumatized. Also, because the needle and suture pierce through the target tissue, it too is traumatized. After the surgery is complete, each layer of tissue through which the incision was made must be sutured and, therefore, is further traumatized. In addition, the method described above with sutures can be time consuming and tedious.
Another disadvantage arises during use of a conventional tissue pick in minimally-invasive surgeries. For example, in order to effectively grasp the target tissue, the tissue pick must be substantially orthogonal to the surface of the target tissue so that the tissue grasping end of the tissue pick can embed into the target tissue. This is sometimes difficult if not impossible to achieve, given the restricted surgical field.